Assessment of Gluta renghas L. and Mangifera indica L. (Sapindales: Anacardiaceae) extracts on the sublethal effects of dengue vector

Wan Fatma Zuharah,Ali Yousaf 한국응용곤충학회 2016 Journal of Asia-Pacific Entomology Vol.19 No.4

Botanical extracts are one of the effective alternative methods for controlling dengue vectors.Methanolic extracts of Gluta renghas Linnaeus and Mangifera indica Linnaeus were assessed under the field condition for substantial lethal and in the laboratory for sublethal effects on dengue vectors in different seasons (dry and wet), and conditions (shaded and unshaded). The effectiveness of these plant extractswas evaluated for the Aedes mosquitoes on the number of eggs, percentage survival of adults, development days to reach adulthood, the number of eggs laid by F1 generation and percentage of hatchability. Significant differenceswere observed for the number of eggs in both the conditions and weeks of collection (P b 0.005) with the least number of eggs recorded by the Mn. indica stem treatment in the dry season. Whereas, Gl. renghas leave extract had the lowest percentage (33.51 ± 2.75%) of surviving adults under the dry shaded conditions. Significant effects were noticed for both conditions and weeks on the percentage of Aedes survived adults and the time to take to reach adulthood (P b 0.005) during both seasons. Mangifera indica stemtreatmentwas observed caused prolong in time for emergence to adult stage in dry unshaded conditions (12.42 ± 0.29 days) and significantly reduced the fecundity of the F1 generations in both seasons (P b 0.005)with less hatching percentage at 55.67±4.24% duringwet shaded conditions.Overall, both plant extracts performed effectively and better than Abate to control Aedes population in the dry season. It can be concluded, that both plant extracts are potential candidates for alternative source of biolarvicides. ©

Susceptibility and fitness cost of Aedes albopictus on their survivability after the exposure to the insecticide

Wan Fatma Zuharah,Aminoddin Sumayyah,Hamady Dieng 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.2

The present study was undertaken to investigate the lethal and sub-lethal effects of insecticides on the life history of Aedes albopictus mosquitoes from urban and sub-urban areas in Penang, Malaysia. The female mosquitoes aged two to five days old were exposed to; (1) diagnostic dose (lethal dose) at 5% malathion and 0.75% permethrin; and (2) sub-lethal concentration of 1.5% malathion, and 0.2% permethrin, respectively and adult female survivors from sub-lethal concentrations were evaluated for fitness parameters. Fecundity, fertility, adult longevity, development time and survival of mosquitoes were the crucial point in their life history had studied. Aedes albopictus species from urban Sg. Dua strain has developed high resistance towards 0.75% permethrin and was confirmed on resistance after 24 h of reading. While sub-urban Batu Maung strain is still susceptible to both 5% malathion and 0.75% permethrin. At the sub-lethal dose, we discovered 0.2% permethrin insecticide have significantly more effects on the fitness cost of Ae. albopictus as compared to 1.5% malathion; with decreasing on fecundity, lesser time was needed to reach each development stages, and more male adult was emerged compared to female mosquitoes for both urban and sub-urban strains. Whereas, malathion insecticide only affected the number of eggs laid by the parent mosquitoes and the development time to reach adult stages. Even though, Ae. albopictus mosquitoes had developed resistance towards permethrin resulted in decreasing mortality, but subsequent effects on their fitness cost still continued on the first generation. Thus, it will benefit in reducing the transmission of mosquito-borne diseases.

Pathogenicity of entomopathogenic fungus, Metarhizium anisopliae MET-GRA4 isolate on dengue vectors, Aedes albopictus and Aedes aegypti mosquito larvae (Diptera: Culicidae)

Zuharah Wan Fatma,Rohaiyu Md Rodzay,Azmi Wahizatul Afzan,Nagao Hideyuki 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.2

Considering the rapid transmission of the dengue virus, substantial efforts need to be conducted to ward-off the epidemics of dengue viruses. The control effort is depending on chemical insecticides and had aroused unde sirable conflicts of insecticide resistance. Here, we study the entomopathogenic fungus, Metarhizium anisopliae as a promising new biological control agent for vector control. The pathogenicity effects of Metarhizium anisopliae against field and laboratory strains of Aedes albopictus and Aedes aegypti larvae were tested using the larvicidal bioassay technique. The results demonstrate that the treatments using M. anisopliae isolate MET-GRA4 were highly effective and able to kill 100% of both Ae. albopictus and Ae. aegypti mosquito larvae at a conidia con centration of 1 × 10⁶/ml within 7 days of the treatment period. The fungus displayed high larvicidal activity against laboratory and field strain of Ae. aegypti larvae with LC 50 values (9.6 × 10 3 /ml, 1.3 × 10 3 /ml) and LC 95 values (1.2 × 10⁶/ml, 5.5 × 10 5 /ml) respectively. For Ae. albopictus, LC 50 values for laboratory and field strains were (1.7 × 10 4 /ml, 2.7 × 10 4 /ml) and the LC 95 values were (2.1 × 10⁶/ml, 7.0 × 10 5 /ml) respectively. Interestingly, the susceptibility of field strain towards M. anisopliae was higher as compared to the laboratory strain Aedes larvae. In which, the causative agents of all the dead larvae were verified by the virulence of M. anisopliae and caused morphological deformities on larval body. The findings from this study identify this isolate could be an effective potential biocontrol agent for vector mosquitoes in Malaysia.

Sex before or after blood feeding: Mating activities of Aedes aegypti males under conditions of different densities and female blood feeding opportunities

Hamady Dieng,Tomomitsu Satho,Fatimah Abang,Erida Wydiamala,Nur Faeza Abu Kassim,Nur Aida Hashim,Wan Fatma Zuharah,Gabriel Tonga Noweg 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.1

Blood feeding and mating are critical behaviors that regulate both mosquito population maintenance and disease transmission. However, our understanding of mosquito mating systems remains incomplete. One of the most critical issues is a lack of understanding regarding how and where males and females encounter one another. This study was performed to investigate changes in key mating behaviors of Ae. aegypti relative to female blood feeding opportunities, taking into account male density. We compared courtship latency and copulation activity between single and pooled males in a range of assays performed in the presence or absence of a blood source and after blood feeding. The time taken by grouped males to initiate courtship in the presence of a host was much shorter than that in single males. There was no significant difference in courtship latency between pooled and single males in the absence of a blood source or after blood feeding. At low male density, the presence of the host and blood meal ingestion provided better conditions for copulation. At high male density, however, copulation activity was decreased after blood feeding, but remained high regardless of the presence or absence of the host. In addition to providing insight into the mating ecology of Aedes aegypti, this study indicated that the presence of a blood source influences how males encounter and copulate with females. The observation that copulation activity decreases after blood feeding when males are numerous provides new avenues for improving mass release programs of sterile mosquitoes.

Changes in the biting activity of a dengue vector relative to larval and adult nutritional histories: Implications for preventive measures

Hamady Dieng,Ooi Seow Hui,Ahmad Abu Hassan,Fatimah Abang,Idris Abd Ghani,Tomomitsu Satho,Fumio Miake,Hamdan Ahmad,Yuki Fukumitsu,Wan Fatma Zuharah,Abdul Hafiz Ab Majid,Nur Faeza Abu Kassim,Nur Aida Ha 한국응용곤충학회 2015 Journal of Asia-Pacific Entomology Vol.18 No.3

Themagnitude of dengue transmission depends largely on the level of human–vector contact. Therefore, knowledge regarding the biting periodicity ofmosquitoes is crucial to determine transmission periods' risk, and in planning personal protection measures. Dengue vectors are day-active and endure transitory periods of starvation overnight. However, it is unclear howtheir blood feeding activity pattern is related to body sizewhen temporarily deprived of their main source of energy — sugar. We examined the changes in Aedes albopictus diurnal biting activity, taking into account larval nutritional history and adult starvation. Overall, large body size and nonstarvation conditions were associated with better blood feeding success, but these parameters did not significantly modify the timing of first blood feeding attempt. Females of both sizes showed significant temporal variations in their blood feeding activities. Under conditions of starvation, blood meal uptake was much greater in large females from morning to evening. Similar variations of feeding activity were observed in small females, except in the morning. Under non-starvation conditions, the blood feeding activity of small mosquitoes tended to decrease over time, whereas blood meal uptake activity was high and remained almost constant from morning to evening for larger mosquitoes. Thiswork emphasizes the importance of body size and hunger on the dynamics of vector–host interaction and has important implications for the development of novel strategies for the prevention of disease transmission. Knowingwhen dengue vectors actively bite during the day can help in timing effective personal protective measures.